1. Field of the Invention
This invention relates to apparatus for holding conduit in a trench and, more particularly to apparatus disposed on top of conduits in a trench and extending between the sides of the trench.
2. Description of the Prior Art
In construction, trenches are dug to receive conduits. The conduits are used for different things, such as liquids (water), electrical conductors, etc. Typically, there are several conduits in a single trench. After the conduits are disposed in a trench, the trench is sometimes back filled with concrete. The conduits have a tendency to rise in the concrete as the concrete is being poured, and in order to prevent the conduits from rising, the conduits must be held in place in some manner.
In the prior art, the conduits are individually fastened in place in some manner or disposed in or on forms or “chairs” in a relatively time consuming and expensive manner. Typically, the use of forms also utilizes vertically oriented spikes to hold the forms in place. Such spikes are disliked by installers.
The following patents have been brought to the attention of the inventor:
U.S. Pat. No. 3,464,661 (Alesi, Jr.) discloses apparatus for supporting conduits in a trench. The conduit holding apparatus includes stackable forms for holding a plurality of conduits in spaced relation. The apparatus is held in place in a trench by vertically oriented spikes 33, as shown in FIGS. 1 and 2. The spikes have problems and the spike approach is not favored by installers. The present apparatus utilizes end plates to secure a horizontally extending element above the conduits to hold the conduits in a trench. The present apparatus may be used with the Alesi basic structure in place of the vertical spikes. The present apparatus is disposed above the top row of conduits to hold the conduits in the trench.
U.S. Pat. No. 4,183,484 (Mathews) discloses another type of conduit spacing apparatus. The apparatus is designed to hold conduits of different diameters in a trench. See FIG. 8. The apparatus also uses vertically oriented spikes for holding the apparatus in a trench, and is thus again not favored by installers. Again, the present apparatus may be used with the Mathews apparatus as discussed above.
U.S. Pat. No. 4,518,1414 (Parkin) discloses apparatus for supporting a fixture to a ceiling, such as a ceiling fan. The apparatus is secured between ceiling joists by joist-engaging blocks mounted on the ends of a threaded support member. The threaded support member thus expands upon the rotation of a center element to drive the spike ends of the blocks into the joists. This apparatus is completely unlike the present invention. The present invention utilizes a pair of end plates that are secured to the walls of a trench completely independently of the structure between the end plates.
U.S. Pat. No. 4,601,447 (McFarland) discloses a conduit spacing and anchoring apparatus which again utilizes vertically oriented spikes (rebar alements) to anchor the conduit holding elements in a trench. The apparatus is accordingly subject to the same deficiencies noted above for the apparatus which use such anchoring elements. Again, the present apparatus may be used with the McFarland structure to secure the conduits in a trench and thus overcome the vertical spike problems, as discussed above.
U.S. Pat. No. 5,827,441 (Solbjorg) discloses another type of conduit stacking and retaining apparatus. The elements which hold the conduits or pipes are secured to panels 8, as shown in FIGS. 1c, 1d, and 7. The conduit holding elements are not secured to the walls of the trench. The present invention may be used with the basic conduit or pipe holding elements to secure the conduits or pipes to the walls of the trench, thus obviating the requirement for the panels 8 and the elements 19 and their associated elements. See FIG. 7 and column 3, particularly lines 50–64.
None of the patents discussed above disclose or in any way suggest that conduits may be retained in place utilizing end plates which may be secured to the walls of a trench. In all cases, the present apparatus may be used with the conduit holding elements by being using the end plates secured to trench walls and then by placing the center bridge element over the conduits and securing the bridge element to the end plates.
The apparatus overcomes the deficiencies in the prior art by providing a retainer disposed on top of the conduits and extending between the sides of the trench. The retainers may be placed on the conduits in a spaced apart manner in the trench quickly and easily and the retainers are relatively inexpensive to manufacture.